Microsoft Outlook is going to work a lot more like Facebook

Facebook-style likes and mentions are coming to Microsoft Outlook
in the web browser, the company announced this week in a
blog entry.

Basically, you'll be able to "like" an e-mail in a chain, and
those likes will show up to everybody in the e-mail thread.
Microsoft says this is designed to highlight the most important,
relevant messages in a thread for further discussion.

Microsoft

There will also be mentions.

Type an "@" sign before someone's name within an email, just like
on Facebook, and they'll get notified that they've been involved
in the discussion. That "@" sign will also appear next to the
subject line if you've been tagged in an e-mail.

Mentions on Microsoft
Outlook.comMicrosoft

Right now, likes and mentions are only coming to Office 365
users in businesses who are on the early release track.
But eventually, Microsoft promises (or threatens), it'll come to
the desktop versions of Office, as well as the iOS and Android
versions of Outlook.